Projections: an old diagnostic tool revisited

David C. Henley

ABSTRACT

Many kinds of projections have been used to help analyze seismic
data over the history of seismic exploration, probably the most
familiar being the CMP stack. We explore here various projections
with an eye to adapting them for particular kinds of analysis. We
present, as an example, several different projections applied to a
4D (time-lapse) seismic experiment in central Alberta and discuss
the diagnostic possibilities of projections in this setting.

While we draw no conclusions in this work, we review the topic of
projections in order to stimulate thinking about new ways in which
to summarize and analyze multi-dimensional data volumes. In the
figure below, from the time-lapse experiment, only projection (a) is
a function of surface location; the other projections are
raypath-dependent. In projections (b), (c), and (d), anomalies seem
slightly more visible than when they are projected along surface
location (better seen at higher magnification).